<template>
  <div>
    <table border="1" width="700" style="border-collapse: collapse">
      <caption>
        购物车
      </caption>
      <thead>
        <tr>
          <th><input type="checkbox" v-model="isAll" /> <span>全选</span></th>
          <th>名称</th>
          <th>价格</th>
          <th>数量</th>
          <th>总价</th>
          <th>操作</th>
        </tr>
      </thead>
      <tbody>
        <tr v-for="(item, index) in goodList" :key="index">
          <td><input type="checkbox" v-model="item.checked" /></td>
          <td>{{ item.name }}</td>
          <td>{{ item.price }}￥</td>
          <td>
            <button @click="item.num > 1 ? item.num-- : 1">-</button>
            {{ item.num }}
            <button @click="item.num++">+</button>
          </td>
          <td>{{ item.price * item.num }}￥</td>
          <td><button @click="deleteFn(index)">删除</button></td>
        </tr>
      </tbody>
      <tfoot>
        <tr>
          <td>合计:</td>
          <td colspan="5">{{ sumPrice }}￥</td>
        </tr>
      </tfoot>
    </table>
  </div>
</template>

<script>
export default {
  data() {
    return {
      goodList: [
        {
          name: '诸葛亮',
          price: 1000,
          num: 1,
          checked: false,
        },
        {
          name: '蔡文姬',
          price: 1500,
          num: 1,
          checked: false,
        },
        {
          name: '妲己',
          price: 2000,
          num: 1,
          checked: false,
        },
        {
          name: '鲁班',
          price: 2200,
          num: 1,
          checked: false,
        },
      ],
    }
  },
  methods: {
    deleteFn(id) {
      return this.goodList.splice(id, 1)
    },
  },
  computed: {
    isAll: {
      get() {
        return this.goodList.every((item) => item.checked)
      },
      set(val) {
        this.goodList.forEach((item) => (item.checked = val))
      },
    },
    sumPrice() {
      if (this.goodList.some((item) => item.checked)) {
        return this.goodList
          .filter((item) => item.checked)
          .reduce((sum, item) => sum + item.price * item.num, 0)
      }
      return 0
    },
  },
}
</script>

<style>
tr {
  text-align: center;
}
</style>
